嗅神经母细胞瘤的CT及MRI影像学表现

目的:探讨鼻腔嗅神经母细胞瘤(ON)的CT及MRI影像学表现特点,以提高对嗅神经母细胞瘤的影像学认识。方法:回顾性分析经手术及组织病理学证实的13例嗅神经母细胞瘤患者的CT及MRI影像学特征及其相关病理学改变。结果:13例患者中,8例行CT平扫,均显示为软组织密度肿块影,其中2例行增强扫描,病灶显著强化;5例行MRI平扫及增强扫描,平扫瘤体信号不均匀,增强后明显不均匀强化。13例中病灶局限于鼻腔者4例;有上颌骨、筛骨、鼻中隔或颅底骨质破坏者9例(69.23%);其中2例侵及同侧的前颅窝(1例有颈部淋巴结转移)。结论:鼻腔中上部肿物,MRI显示内部信号不均匀,而CT显示密度大都较均匀,且增强有明显强化,周围骨质有破坏,甚至病灶自鼻腔延续至前颅窝者,呈"蘑菇"状,应考虑嗅神经母细胞瘤的可能。

CT and MRI Manifestations of Olfactory Neuroblastoma

Objective:To investigate the CT and MRI manifestations of olfactory neuroblastoma(ON) within nasal cavity,in order to improve the understanding and diagnosis accuracy.Methods:The CT or/and MRI features of 13 cases with surgery and pathology proved ON were studied retrospectively and correlated with the pathology findings.Results:Among the 13 cases,8 cases had plain CT showing mass with soft tissue density,2 of them were obviously enhanced after contrast administration.5 patients had MRI,heterogeneous signal intensity of tumor mass on plain MRI could be assessed,showing marked and heterogeneous enhancement after contrast medium was applied.Of the 13 cases,there were 4 cases showing tumor mass limited within nasal cavity;associated bony destruction of maxilla,ethmoid bone,nasal septum,skull base could be seen in 9 cases(69.23%),2 of them showing tumor invasion into anterior cranial fossa.1 case had cervical lymph node metastasis.Conclusion:The diagnosis of olfactory neuroblastoma should be considered when tumor mass located within middle/upper part of nasal cavity,with heterogeneous signal intensity on MRI or homogeneous soft tissue density on plain CT and marked enhancement after contrast administration with adjacent bony destruction.Tumor even could expand into the anterior cranial fossa,showing a mushroom-like tumor mass.